Protein linked to heart failure

Elevated levels of the protein CIB1 causes enlargement of the heart and subsequent heart failure, according to rodent research.

Cardiac hypertrophy is a condition in which the heart muscles thicken, leading to an enlarged and weakened heart. The cells which increase in size, usually after a heart attack or from high blood pressure, are called cardiomyocytes. To identify the factors regulating cardiomyocyte growth, researchers examined neonatal rat heart cells genetically altered to become hypertrophic, which led to the discovery of elevated CIB1 levels.

They also analysed mouse and human heart cells with similar results. To deduce the function and interactions of CIB1 during hypertension they studied the protein in GM mice. One group of mice was designed to lack CIB1, the other to over-express it. The group with high blood pressure and excess CIB1 exhibited cardiac hypertrophy, but mice without CIB1 were protected. Scientists also discovered that the protein activated the enzyme calcineurin.

Calcineurin is known to be important in the development and function of heart cells. Although more research is needed on CIB1 and calcineurin, the team suggests that both insights may be used to prevent heart failure.